New metrics reveal the evolutionary continuum behind the morphological diversity of subglacial bedforms

Vérité, Jean; Ravier, Édouard; Bourgeois, Olivier; Bessin, Paul; Pochat, Stéphane

doi:10.1016/j.geomorph.2023.108627

Cited by 4 publications

(5 citation statements)

References 113 publications

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“…low hydraulic connectivity and enhanced ice bed-coupling). Such an explanation would be compatible with the model of bedform continuum between ribbed, transitional and streamlined bedforms primarily controlled by a gradient of bed deformation (Aario, 1977;Ely et al, 2016;Vérité et al, 2023). This hypothesis is also supported by ribbed bedforms within SMCs that are consistently transverse to the orientation of both SMC axis and surrounding streamlined bedforms (Figures 9c-d).…”

Section: Ribbed Bedforms Form Contemporaneously With the Onset Of Sub...supporting

confidence: 80%

“…In both Fennoscandia (Peterson et al, 2017) and northern Canada (Lewington, 2020; Vérité et al, 2023), some of these narrow corridors of ribbed bedforms have been associated with SMCs (Figure 2d). Furthermore, some of these ribbed bedform corridors are spatially associated with hummocks and murtoos along or in the vicinity of SMCs (Peterson et al, 2017; Remmert & Kristiansson, 2018; Ojala et al, 2019; Ahokangas et al, 2021; Vérité et al, 2022).…”

Section: Review Of Bedforms and Landforms Identified Within Smcsmentioning

confidence: 99%

“…Iverson et al, 2007; Piotrowski & Kraus, 1997). Therefore, it seems reasonable to explore the potential formation of narrow and flow‐parallel tracts of ribbed and streamlined bedforms (Dunlop & Clark, 2006; Wagner, 2014) in the context of subglacial drainage routes (Lewington, 2020; Peterson et al, 2017; Vérité et al, 2023).…”

Section: Processes Of Bedform Formation Within Smcsmentioning

confidence: 99%

Section: Ribbed Bedformsmentioning

confidence: 99%

“…Streamlined bedforms and streamlined ribbed bedforms commonly coexist in the vicinity of ribbed bedforms and SMCs. In some cases, streamlined ribbed bedformsreferred to as transitional bedforms byVérité et al (2023) form lateral transitions between ribbed (inside the SMC) and streamlined bedforms (outside the SMC) and typically delineate SMC margins (Figure9d). Ribbed bedform tracts are commonly associated with murtoo tracts along SMCs.…”

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confidence: 99%

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Conceptual model for the formation of bedforms along subglacial meltwater corridors (SMCs) by variable ice‐water‐bed interactions

Vérité,

Livingstone,

Ravier

et al. 2023

Earth Surf Processes Landf

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Subglacial meltwater landforms found on palaeo‐ice sheet beds allow the properties of meltwater drainage to be reconstructed, informing our understanding of modern‐day subglacial hydrological processes. In northern Canada and Fennoscandia, subglacial meltwater landforms are largely organized into continental‐scale networks of subglacial meltwater corridors (SMCs), interpreted as the relics of subglacial drainage systems undergoing variations in meltwater input, effective pressure and drainage efficiency. We review the current state of knowledge of bedforms (hummocks, ridges, murtoos, ribbed bedforms) and associated landforms (channels, eskers) described along SMCs and use selected high‐resolution DEMs in Canada and Fennoscandia to complete the bedform catalogue and categorize their characteristics, patterning and spatial distributions. We synthesize the diversity of bedform and formation processes occurring along subglacial drainage routes in a conceptual model invoking spatiotemporal changes in hydraulic connectivity, basal meltwater pressure and ice‐bed coupling, which influences the evolution of subglacial processes (bed deformation, erosion, deposition) along subglacial drainage systems. When the hydraulic capacity of the subglacial drainage system is overwhelmed glaciofluvial erosion and deposition will dominate in the SMC, resulting in tracts of hummocks and ridges arising from both fragmentation of underlying pre‐existing bedforms and downstream deposition of sediments in basal cavities and crevasses. Re‐coupling of ice with the bed, when meltwater supply decreases, facilitates deformation, transforming existing and producing new bedforms concomitant with the wider subglacial bedform imprint. We finally establish a range of future research perspectives to improve understanding of subglacial hydrology, geomorphic processes and bedform diversity along SMCs. These perspectives include the new acquisition of remote‐sensing and field‐based sedimentological and geomorphological data, a better connection between the interpreted subglacial drainage configurations down corridors and the mathematical treatments studying their stability, and the quantification of the scaling, distribution and evolution of the hydraulically connected drainage system beneath present‐day ice masses to test our bedform‐related conceptual model.

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Section: Ribbed Bedforms Form Contemporaneously With the Onset Of Sub...supporting

confidence: 80%